Electronic device with body-biasing circuit for portable equipment with USB connector for headset

摘要

The invention relates to an electronic device (101) comprising:
- a electrical portion (102) arranged to operate at a first reference voltage (VUSB) and at a second reference voltage (VCCHS), the electrical portion (102) comprising:
- a digital data transmission stage (103) having at least a first output terminal (03) to provide a first digital signal (D1) having a voltage value corresponding to the first reference voltage (VUSB) or to a further reference voltage (GND);
- a audio signal amplification stage (104) comprising at least an amplifier (105) having an output stage (106) comprising a PMOS transistor (MP) and a NMOS transistor (MN) connected in series one another between said second reference voltage (VCCHS) and a further reference voltage (VSSHS), said output stage (106) having a respective output terminal (05) connected to said at least first output terminal (03) of the digital data transmission stage (103) to provide an output signal (OUT), said output signal (OUT) corresponding to said first digital signal (D1) in a digital data transmission mode of the electrical portion (102) or to an audio signal (HSL) in an audio amplification mode of the electrical portion (102);
- at least one biasing circuit (107) of the body terminal (B) of the PMOS transistor (MP) of said output stage (106). The electronic device (101) is characterized in that the at least one biasing circuit (107) is arranged to supply to the body terminal (B) of the PMOS transistor (MP) of the output stage (106) a biasing voltage (VbMP) corresponding to the highest between the voltage value of the output signal (OUT) and the second reference voltage (VCCHS) of the electrical portion (102) of the electronic device (101).